Deductions & credits

You may be limited by the taxable income reported for the self-employment activity.  IRS Instructions for Form 4562, here, states:

Page 4 Line 11 

The total cost you can deduct is limited to your taxable income from the active conduct of a trade or business during the year.

Or you may be bumping into the IRS Depreciation Limits discussed in IRS Publication 463 Travel, Gift, and Car Expenses.  See page 24 Limit for sport utility and certain other vehicles here. 

You cannot elect to deduct more than $28,900 of the cost of any heavy sport utility vehicle and certain other vehicles placed in service during the tax years beginning in 2023.

There are limits on the amount that you may deduct for depreciation of your vehicle.  The section 179 deduction and special depreciation allowance are treated as depreciation for purposes of the limits.